It is March in New England, you’re walking across a frozen lake and the two Samoyeds look like white fluffy clouds prancing by your side. Every footfall is greeted with an icy moan of disapproval and you have time to consider the warmth of the morning sun, hinting at a thaw, before the glass below your feet suddenly shatters and one of your beloved dogs slips into the darkness below. Quick, immerse yourself in this moment and take the same split second to think, “Do I risk my own life for the life of my dog?”

If your answer is yes, you are not alone. Ninety-three percent of pet owners say they would risk their life for their pet, and on March 26, 2005, John Harsh was one of them. He ran to save his puppy, Tobin, and instinctively, Rocky, his loyal dog of seven years, ran to save John. All three fell through the ice. The two dogs survived, but tragically, John succumbed to hypothermia, pulled from the water still clinging to Rocky’s leash.

A breathy “Wow,” was all I could muster the first time I heard this story from Rocky’s new owner, Joanna, as I petted the smiling, enormous white puff ball. I didn’t have a comeback for this kind of introduction, though a question crossed my mind: Can dogs feel survivor’s guilt?

Over the intervening years, I have seen Rocky for various orthopedic ailments, but one day, he presented with a vague yet disturbing malady.

“He keeps waking up in the night, screaming and howling in pain, unable to get comfortable. I can’t tell what’s hurting him but whatever it is, he can’t get back to sleep.”

My physical examination of Rocky was unremarkable, so I took a sample of his blood and to my surprise, some of his white blood cells were off the charts. “It’s weird,” I told Joanna, “his blood is acting like he’s got a serious infection somewhere in his body, but his temperature is completely normal.”

I reckoned these little white cells were trying to tell me something, so we went hunting for clandestine disease. An ultrasound of Rocky’s abdomen hit pay dirt. There were several golf-ball-sized lumps in his spleen and liver, and I didn’t need the sharp intake of breath from the ultrasonographer to appreciate what the grainy films were showing us in such stark relief. They say two-thirds of splenic tumors are cancerous, but given the changes on Rocky’s liver and the possibility of local spread, I thought those odds might be too generous.

I told Joanna of my findings. “It’s possible the tumors are causing pain. It’s possible they are infected. Either way, I think we need to take them out.” “Are you sure it’s worth it?” she asked. “From what you’re telling me, the chance of this being something benign is pretty slim.”

I thought about her question, “Is it worth it?” and I realized I was being biased. How could you not be swayed by Rocky’s history? This dog’s life had been traded for a human life and every time I was around him, I felt a responsibility to make his survival count for something, to help him live the biggest dog life possible as the ultimate show of gratitude.

“I just don’t see a dog that’s ready to quit. If Rocky is going to die, I reckon he’d rather die trying. To me, he still looks like a dog with something to prove.” Joanna agreed, and I went in.

The tumors, which really do look remarkably like golf balls—a pale, firm, discreet trio of them—were deftly removed with no surprises. I called Joanna after surgery, careful to remain neutral as to what I found. I have been burnt too many times—better to have pessimism surprised than optimism crushed. Think positive but brace, just in case.

As it turned out, each nodule was benign and harmless, and by the time Rocky’s staples were removed, Joanna reported no further bouts of nocturnal pain. Rocky was happy, spirited and enjoying his beauty sleep, but still, the pathologists had failed to discover the underlying cause of his infection. Frustrated, I persuaded Joanna to let me take one more look at his blood and, to my horror, it still revealed abnormal white blood cells in abundance. Despite Rocky’s apparent recovery, had I put him through surgery and still not gotten rid of his problem?

It took an astute pathologist to set me straight. “Rocky has ‘Pelger-Huet Anomaly.’ It’s a genetic disorder of dogs, particularly seen in Australian Shepherds, Foxhounds and, of course, Samoyeds. It can make certain white blood cells look all wrong, even though they function fine. Affected dogs should be perfectly healthy. So long as you know what it is, you won’t mistake it for an infection or, worse still, a condition like leukemia.”

I contacted Joanna to tell her the good news. “For all the wrong reasons, Rocky sent me on a wild goose chase and we ended up finding his problem after all.” Some six months later, Joanna sent me a photo of Rocky celebrating his 12th birthday. “He’s doing great, never looked back,” she told me.

And on hearing this news, I dared to ask my question about Rocky’s burden of guilt. “All I know,” she said, “is Rocky loves life. Perhaps John’s greatest legacy was saving a dog that could come out of such a horrific tragedy and still be warm, loving and fearless. He is the biggest bundle of unconditional love you could ever hope to have in your life.”